The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Generally, the rotation of the crankshaft of internal combustion engines is not uniform because of the work cycles associated with the pistons of the engines. This non-uniformity increases with decreasing number of cylinders, low speeds, and high loads. Attempts to counteract these rotation irregularities include torsionally connecting a large mass to the crankshaft. For example, a linkage system has been employed between a flywheel and a crankshaft so that the flywheel oscillates relatively to the crankshaft the same number of times per crankshaft revolution as the combustion event. The linkage is arranged such that the counter torque generated by the oscillations of the flywheel is in the opposite direction of the engine torque. In these arrangements, however, only the magnitude (and not the phase) of the counter torque generated by the flywheel oscillation is adjustable, even though both the phase and the magnitude of the engine torque fluctuation changes with the engine speed and load.